The use of diesel engines has increased substantially in recent years, particularly in the automotive field. This increased popularity is due to, among other things, improved fuel mileage in comparison to today's standard gasoline engine. In addition, diesel engines typically produce emissions at significant reduced pollutant levels when compared to those of standard gasoline engines. One problem associated with diesel engines, however, is that they have been characteristically difficult to start in cold weather. This is due primarily to an inherent tendency of the diesel fuel to gel in sufficiently cold temperatures, thus causing such starting difficulties. In addition, engines which use fuels in this condition possess a relatively high tendency to stall, even after having been successfully started.
To overcome this problem fuel line heaters have been utilized, such as the variety that employs a resistance wire wrapped within an insulator. However, heaters of this variety, typically located along the fuel line supplying the engine, have not proven to be very efficient.
In Ser. No. 334,292, filed Dec. 4, 1981 and entitled "Diesel Fuel Heater" (Inventor: David A. Siefer), there is defined a fuel heater which employs at least one positive temperature coefficient thermistor located in the fuel passage of the heater's housing for raising the temperature of the fuel passing therethrough to hopefully reduce gelling. One drawback of this heater, however, is that it is not readily adaptable to currently existing diesel filter components (those typically employing an upper filter housing and a lower spin-on disposable filter), thus requiring substantial modification to such designs in order to incorporate the advantages of this heater therein.
It is believed, therefore, that a diesel fuel heater which is readily adaptable for use as a retrofit in existing diesel fuel filter components to provide the several substantial advantages cited hereinbelow would constitute a significant advancement in the art. It is further believed that a combined diesel fuel heater and heater assembly possessing the advantageous features cited hereinbelow would constitute an art advancement. It will be also understood from the following description that the instant invention possesses other distinguishing features than those cited above when compared to the device described in Ser. No. 334,292 including, among other things, an improved means for coupling electrical power to the compact fuel heater component.